Write expression in the form a + bi, where a and b are real numbers?

0 ⤊

-3i(4i - 1)

2007-02-25 04:45:00 · 4 answers · asked by I can help 1 in Science & Mathematics ➔ Mathematics

-3i(4i - 1)

Distribute the -3i.

-12i^2 + 3i

Note that i^2 = -1. Change it to be like that.

-12(-1) + 3i

Evaluate normally.

12 + 3i

2007-02-25 04:48:04 · answer #1 · answered by Puggy 7 · 0⤊ 0⤋

You need to distribute. The important thing to remember is that i*i=-1

-3i(4i - 1)
-12i*i+3i
-12*-1+3i
12+3i

2007-02-25 12:49:42 · answer #2 · answered by Anonymous · 0⤊ 0⤋

distribute

-12i^2 + 3i

i^2 = -1

-12(-1) + 3i

12+3i

2007-02-25 12:53:30 · answer #3 · answered by 7 · 0⤊ 0⤋

So, multiply it out.

2007-02-25 12:48:03 · answer #4 · answered by arbiter007 6 · 0⤊ 0⤋